HELSINKI — China is planning to expand its Tiangong space station with a multi-functional module to enhance its capabilities.

China completed the construction of the three-module Tiangong space station last November, realizing a plan first approved in 1992. 

The operational phase of the station began with a first crew handover late last year. China plans to keep Tiangong permanently inhabited for at least a decade with crews of three spending six months at a time in orbit.

Already though, new plans are emerging. “We will launch the expansion module of the space station at an appropriate time to further expand the size of the space station and enhance its capacity,” Ji Qiming, assistant to director of the China Manned Space Engineering Office (CMSEO), told CCTV Feb. 24.

The expansion module appears to have superseded earlier an apparent plan to send up duplicates of the existing three, roughly 20-metric-ton modules.

The multi-functional expansion module will host six docking ports and turn the T-shaped Tiangong into a cross-shaped configuration.

The added ports will provide redundancy and allow more spacecraft to dock at Tiangong than present. This would also help facilitate plans to allow commercial spacecraft and tourist visits to the orbital outpost.

Ji discussed the expansion plan with Chinese state media at an exhibition to mark three decades of China’s human spaceflight program. He also revealed progress on China’s plans to land astronauts around the end of the decade.

Tianhe, the space station core module, was the first piece of the station to be launched back in April 2021. It provides the main propulsion and life support systems and crew quarters for the astronauts on Tiangong and carries a docking hub to facilitate the arrival of spacecraft and further modules.  

Images from facilities at the China Academy of Space Technology (CAST), the maker of China’s space station modules, suggested that backup or engineering models had been developed and could be readied for use in orbit. 

The smaller, multi-functional module resembles some outward design features of Tianhe but would not require all of the core module’s systems and capabilities to be replicated. Its docking ports would however still allow for the arrival of new experiment modules to expand further.

The country will also launch a co-orbiting optical telescope module, named Xuntian, in 2024. It will be capable of docking with Tiangong for repairs, maintenance, refueling and upgrades.

In an adjacent development, CMSEO officials revealed that it is preparing for international visits to Tiangong.

“We are about to start selecting international astronauts to send to our space station and carry out scientific experiments together,” Chen Shanguang, a deputy chief designer of China’s human spaceflight program, told CCTV.

“Coming to China’s space station and taking a Chinese rocket to space requires familiarity with China’s spacecraft. This may have to wait until they arrive in China so that our instructors can train them,” Chen said.

The move is part of China’s plans to use Tiangong to boost its international space cooperation and soft power.

Many countries have proposed sending astronauts to visit Tiangong, according to Chen, who did not name specific states. 

The European Space Agency will not be sending its astronauts, however, despite earlier training exchanges with China. ESA Director General Josef Aschbacher said in January that the agency had neither the budget nor the political green light for participating in the Chinese space station.

Meanwhile experiments selected by a joint program between the CMSA and the United Nations Office for Outer Space Affairs (UNOOSA) could begin flying to Tiangong this year.

Andrew Jones covers China's space industry for SpaceNews. Andrew has previously lived in China and reported from major space conferences there. Based in Helsinki, Finland, he has written for National Geographic, New Scientist, Smithsonian Magazine, Sky...